The present invention relates to an airbag for protecting a vehicle occupant in the event of vehicle collision, and specifically relates to an airbag having a left half airbag to be inflated at a front left of the occupant, and a right half airbag to be inflated at a front right of the occupant. The present invention also relates to an airbag device provided with the airbag and a vehicle provided with the airbag device.
Japanese Patent Publication (KOKAI) No. 04-292239 has disclosed an airbag for protecting a vehicle occupant in the event of vehicle collision. The airbag has a left half airbag to be inflated at a front left of the occupant, and a right half airbag to be inflated at the front right of the occupant. A common inflator inflates both the left half and right half airbags. In the airbag, a distal end of the left half airbag is connected to a distal end of the right half airbag with a tie panel.
The airbag is folded in a case and covered with a cover. In the event of vehicle collision, an inflator, i.e. a gas generator, injects gas to inflate the airbag rapidly in front of the occupant by pushing and opening the cover.
The inflator is disposed at an inside or outside of a base portion of the airbag. In an airbag device having an inflator disposed at an outside of the base portion of the airbag, the gas from the inflator is supplied into the airbag through a gas inlet disposed at the base portion side of the airbag. In an airbag device having an inflator disposed at an inside of the base portion side of the airbag, the inflator is entirely or partially disposed in the airbag. An example of the latter case includes a configuration in which a pair of slit openings is formed in the airbag, and a rod inflator passes through the slit openings, so that both ends of the inflator expose at the outside of the airbag.
As airbags for protecting vehicle occupants, there are a curtain airbag to be expanded along a side portion of a vehicle cabin (side door or B pillar), a knee airbag to be expanded in front of a leg of an occupant, a side airbag to be expanded toward a side of an occupant, and a seat cushion airbag to be expanded at a lower front side of a seat cushion to left or harden a front portion of the seat cushion. The seat cushion bag lifts or hardens the front portion of the seat cushion to prevent so-called submarine phenomena in which an occupant slides down under a seat belt in case of vehicle collision. Japanese Patent Publication (KOKAI) No. 2001-247010 has disclosed such a seat cushion airbag.
In the airbag disclosed in Japanese Patent Publication No. 04-292239, the distal ends of the left half and right half airbags are connected with the tie panel. Therefore, when the airbag is inflated, the tie panel receives a center part of the vehicle occupant's body in the lateral direction. When the left half and right half airbags are inflated, a larger amount of the gas may flow in one of the half airbags from the inflator, and then the other of the half airbags is inflated later than the one of the half airbags.
As described above, the distal ends of the left and right half airbags are connected with the tie panel. Accordingly, it is expected that when one of the half airbags is inflated faster than the other, the one of the half airbags may facilitate the other of the half airbags to be inflated by pulling the other of the half airbags through the tie panel. As described above, however, the tie panel connects the distal ends of the left and right half airbags. Therefore, the one of the half airbags does not sufficiently pull the other of the half airbags through the tie panel until the one of the half airbags is inflated up to the distal end.
In view of the problem described above, an object of the present invention is to provide an airbag wherein a left half airbag and a right half airbag are inflated smoothly and substantially uniformly toward left and right sides from an early stage of the inflation.
Another object of the invention is to provide an airbag having a vent hole at an appropriate position.
A further object of the invention is to provide an airbag device provided with such an airbag and a vehicle provided with the airbag device.
Further objects and advantages of the invention will be apparent from the following description of the invention.